PtPd/C catalysts

Feng L, Si F, Yao S, Cai W, Xing W, Liu C (2011) Effect of deposition sequences on electrocatalytic properties of PtPd/C catalysts for formic acid electrooxidation. Catal Commun 12 772-775... 

Gao H, Liao S, Liang Z, Liang H, Luo F (2011) Anodic oxidation of ethanol on core shell structured Ru PtPd/C catalyst in alkaline media. J Power Sources 196 6138-6143... 

Kadirgan, E, Beyhan, S. Atilan, T Preparation and characterization of nano-sized PtPd/C catalysts and comparison of their electro-activity toward methanol and ethanol oxidation. Int. J. Hydrogen Energy 34 (2009), pp. 4312 320. 

The high methanol tolerance of PtPd/C alloy catalysts is attributed to the weak competitive reaction of methanol oxidation, which could be induced by composition effects associated with the presence of Pd atoms. The methanol adsorption-dehydrogenation process requires at least three neighboring Pt atoms with appropriate crystallographic arrangement, so, in the case of Pt-Au/C materials, the probability this arrangement in the surface decreases for increasing Au contents. 

In addition to Pt—Au/C catalysts, several other Pt-based alloy catalysts, such as PtCo/C, PtNi/C, PtV/C, and PtPd/C were also reported, and the mechanism of enhancing ORR activity was investigated using both RDE and RRDE techniques. The mechanism of ORR improvement by alloying is ascribed to (1) increase in the catalyst surface roughness,(2) decrease in the coverage of surface oxides and an enrichment of the Pt-active sites of the catalyst surface,(3) increase in the d-orbital vacancy, which strengthened the Pt—O2 interaction, and (4) decrease in the Pt—Pt distance and the Pt—Pt coordination numbers. Table 7.4 lists the properties of PtCo/C and PtNi/C catalysts and their ORR performance parameters measured by RDE techniques for comparison. 

Wang et al. compared formic acid electrooxidation EIS Nyquist plots for Pt/C and PtPd(aUoy)/C catalyst (Fig. 3.9a, b, respectively) [12]. The results were acquired in 0.5 M formic acid and 0.5 M HCIO4 over a range of applied dc potentials from 0.1 to 0.7 V versus Ag/AgCl (-1-0.199 V vs. RHE). The Nyquist... 

Figure 3.4 Schematics of ORR electrocatalyst s morphologies. (A) Metal catalyst such as Pt and metal alloy catalyst such as PtPd supported on a conductive material such as carbon or metal oxide (B) core—shell catalyst such as Au Pt supported on conductive material such as carbon or metal oxide (C) metal catalyst such as Pt and metal alloy catalyst such as PtPd supported on a nanofibre such as carbon or metal-oxide nanofibre and (D) core—shell catalyst such as Au Pt supported on conductive nanotubings such as carbon nanotubings. (For color version of this figure, the reader is referred to the online version of this book.)...

Fig. 5.2 Cyclic voltammograms of Pt/G (a), PtAu/G (b), PtPd/G (c), and PtPdAu/G (d) catalysts in 1.0 M KOH containing 1.0 M CH3OH solutions with a scan rate of 50 mV s. Reproduced from ref. [37]...

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